Italy is the first European country to implement mandatory B2B e-invoicing. While all domestic transactions are currently sent to the Italian Revenue Agency via Sistema di Interscambio (SDI), for cross border invoices Esterometro system is utilized. This will change starting January 1st 2022 as Esterometro will be abolished and therefore all cross-border invoices will be sent via SDI.
The format used for submitting invoices is the FatturaPa format which recently included the new XML requirement which is mandatory since January.
Purchase invoices from non-resident suppliers must be submitted to SDI by the 15th day of the month following the one in which the document was issued or received and sales invoices towards non-resident customers must be reported within 12 days from the date of the invoice.
Source credit: Pagero.com